Cytotoxic agents can provide therapeutic benefits in the treatment of various conditions, including various cancers. Accordingly, it is desirable to provide cytotoxic agents with therapeutically useful properties, for example, as chemotherapies in cancer treatments.
Clinical uses of cytotoxic agents as chemotherapies usually develop drug resistances, and thus, drop their therapeutic efficacies. Accordingly, it is desirable to provide cytotoxic agents with improved drug resistance profiles. One possibility is to design cytotoxic compounds with efflux pump resistances. Another possibility is to design cytotoxic compounds potentially act on more than one targets.
Tubulins are a class of targets for anti-mitotic agents as chemotherapies alone or in combination with other chemotherapies or as active agent-conjugates. Examples of Tubulin-Binding Agents include, but are not limited to, the following compounds:

Many enzymes, for example, proteasome, MMAP, FAP and uPA, are considered as cancer therapy targets due to their involvements in cancer proliferations and metastases. Examples of Proteasome inhibitors include, but are not limited to, the following compounds:

Example of FAP Inhibitors, not Limited to:

Examples of uPA Inhibitors, not Limited to:

Examples of MMP Inhibitors Disclosed in, not Limited to:
Compounds disclosed in Bioorganic & Medicinal Chemistry 15 (2007) 2223-2268.
Compounds disclosed in Cancer Metastasis Rev (2006) 25: 115-136.